1. Field of the Invention
The invention relates to a buttonhole sewing machine according to the preamble of claim 1.
2. Background Art
German patent 291 197 teaches a buttonhole sewing machine of the generic type, which has a buttonhole cutting device comprising knives of varying shape and size that are disposed in the base plate. Depending on the desired shape of a buttonhole, the corresponding knife can be selected from a plurality of knives of revolver-style arrangement. A device of this type is rather complicated.
U.S. Pat. No. 2,247,305 teaches a device for the production of buttonholes. In this case, a knife cooperates with a cutting block, the length of engagement i.e., the length by which the cutting block and the knife overlap, being adjustable so that buttonhole incisions of varying length can be cut. This design is complicated and not sufficiently flexible.
DE 100 85 290 T1 describes a buttonhole sewing machine which includes an eye-type-buttonhole cutting device. Cuts of varying shape and size can be produced by several cutting motions of a knife.